SIGSEGV safe generation with mutation control

docker-compose.yaml

@@ -1,16 +1,11 @@
 version: '3'
 services:
-  sins_build:
+  sins_run:
     image: sins
     build:
       context: .
     volumes:
       - ${PWD}:/app
     working_dir: /app
-    command: yasm seed.asm -o seed
-  sins_run:
-    image: sins
-    volumes:
-      - ${PWD}:/app
-    working_dir: /app
     command: python3 -m sins
+    # command: yasm seed.asm -o seed

sins/__init__.py

@@ -1,3 +1,3 @@
 #! /usr/bin/env python3
-from .run import sins, shell_func
+from .run import sins, generation
 # from .orm import SeedNode

sins/run.py

@@ -3,29 +3,56 @@ from argparse import ArgumentParser
 from datetime import datetime
 from pathlib import Path
 from random import randint
+from multiprocessing import Process, Queue
+from queue import Empty
 import binascii
 import ctypes
 import logging
-import subprocess
 import mmap
 
-whoami_shell = b"\x6a\x3b\x58\x99\x48\xbb\x2f\x62\x69\x6e\x2f\x73\x68\x00\x53\x48\x89\xe7\x68\x2d\x63\x00\x00\x48\x89\xe6\x52\xe8\x10\x00\x00\x00\x2f\x75\x73\x72\x2f\x62\x69\x6e\x2f\x77\x68\x6f\x61\x6d\x69\x00\x56\x57\x48\x89\xe6\x0f\x05"
-seed_shell = b'U\x90H\x89\xe5\x90H\x89}\xf8\x90H\x8bE\xf8\x90]\x90\xc3'
+template_shell = b''.join([
+    b'\x55',              # push   rbp
+    b'\x48\x89\xe5',      # mov    rbp,rsp
+    b'\x48\x89\x7d\xf8',  # mov    QWORD [rbp-0x8],rdi
+    b'\x48\x8b\x45\xf8',  # mov    rax,QWORD [rbp-0x8]
+    b'\x5d',              # pop    rbp
+    b'\xc3'])             # ret
 
-def shell_func(shellcode: bytes):
-    exec_mem = mmap.mmap(
-        -1, len(shellcode),
-        prot=mmap.PROT_READ | mmap.PROT_WRITE | mmap.PROT_EXEC,
-        flags=mmap.MAP_ANONYMOUS | mmap.MAP_PRIVATE)
+seed_shell = b''.join([
+    b'\x55',
+    b'\x48\x89\xe5',
+    b'\x90' * randint(8, 64),
+    b'\x48\x89\x7d\xf8',
+    b'\x90' * randint(8, 64),
+    b'\x48\x8b\x45\xf8',
+    b'\x5d',
+    b'\xc3'])
+
+
+def flip(shellcode: bytes):
+    shellcode = bytearray(shellcode)
+    offset = randint(0, len(shellcode) -1)
+    flip = randint(0, 255)
+    shellcode[offset] ^= flip
+    return bytes(shellcode)
+
+
+def generation(queue: Queue, shellcode: bytes):
+    prot = mmap.PROT_READ | mmap.PROT_WRITE | mmap.PROT_EXEC
+    flags = mmap.MAP_ANONYMOUS | mmap.MAP_PRIVATE
+    exec_mem = mmap.mmap(-1, len(shellcode), prot=prot, flags=flags)
 
     exec_mem.write(shellcode)
-
     ctypes_buffer = ctypes.c_int.from_buffer(exec_mem)
-    function = ctypes.CFUNCTYPE(ctypes.c_uint, ctypes.c_uint)(
-        ctypes.addressof(ctypes_buffer))
+    addr = ctypes.addressof(ctypes_buffer)
+
+    function = ctypes.CFUNCTYPE(ctypes.c_uint, ctypes.c_uint)(addr)
     function._avoid_gc_for_mmap = exec_mem
 
-    return function
+    shellcode_len = ctypes.c_uint(len(shellcode))
+    result = function(shellcode_len)
+
+    queue.put(result)
 
 
 def sins():
@@ -35,6 +62,8 @@ def sins():
     parser.add_argument('-v', '--verbose', action='count')
     parser.add_argument('-s', '--seed', help='path to PIC image.')
     parser.add_argument('-o', '--output', help='path to results directory.')
+    parser.add_argument('-l', '--lineage', default=10,
+        help='max count of unsuccessful generation.')
     args = parser.parse_args()
 
     log_level = logging.INFO
@@ -70,35 +99,31 @@ def sins():
         with seed.open('rb') as seed_file:
             seed_data = seed_file.read()
 
-    logger.info(f'seed_data\n{seed_data}')
-    logger.info(f'seed_len: {len(seed_data)}')
+    logger.info(f'seed:\n{seed_data}')
 
-    seed = shell_func(seed_shell)
-    ret_val = seed(ctypes.c_uint(len(seed_data)))
+    queue = Queue()
 
-    logger.info(f'ret_val:  {ret_val}')
+    while True:
+        lineage = 0
+        seed_flipped = flip(seed_data)
 
-def func_void(shellcode: bytes):
-    exec_mem = mmap.mmap(
-        -1, len(shellcode),
-        prot=mmap.PROT_READ | mmap.PROT_WRITE | mmap.PROT_EXEC,
-        flags=mmap.MAP_ANONYMOUS | mmap.MAP_PRIVATE)
+        while lineage < args.lineage:
+            logger.info(f'lineage: {lineage}')
+            result = None
 
-    exec_mem.write(shellcode)
+            proc = Process(target=generation, args=(queue, seed_flipped))
+            proc.start()
+            try:
+                result = queue.get(timeout=1)
+            except Empty:
+                lineage += 1
+                continue
 
-    ctypes_buffer = ctypes.c_int.from_buffer(exec_mem)
-    function = ctypes.CFUNCTYPE(ctypes.c_int64)(
-        ctypes.addressof(ctypes_buffer))
-    function._avoid_gc_for_mmap = exec_mem
+            if not result:
+                lineage += 1
+                continue
 
-    return function
-
-
-def example():
-    logging.basicConfig(level=logging.DEBUG)
-    logging.info(whoami_shell)
-    logging.info('wtfm8')
-    whoami = func_void(whoami_shell)
-    ret_val = whoami()
-    # whoami doesn't ret
-    logging.info(ret_val)
+            logger.info(f'scrap:\n{seed_flipped}')
+            logger.info(f'result: {result}')
+            lineage = 0
+            seed_flipped = flip(seed_flipped)